Introduction
Fennel is a flowering plant with a bulb root that can be eaten. Its seeds are used in food and supplements. It has been used to ease the pain of menstrual cramps. Fennel can be taken as a pill, powder, or extract. It can also be used as a cream, gel, or oil.
Dosages
30 milligrams every 4 to 6 hours
What Research Shows
May Be Effective
- Colic —may decrease symptoms A1-A3
- DPMA-induced amenorrhea—may ease symptoms C1
- Dysmenorrhea (Painful Menstruation) —may ease symptoms D1, D2
- Irritable Bowel Syndrome —may improve symptoms when taken with curcuminE1
- Menopausal symptoms —may ease symptoms F1
- Vaginal atrophy—may help manage symptoms G1
Not Enough Data to Assess
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
Safety Notes
It is likely safe to take fennel or use fennel oil on the skin for a short time. Not enough studies have been done to say whether it is safe to use for a long period or during pregnancy or breastfeeding.
Interactions
Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse. People who are allergic to mugwort, birch, or ragweed should talk to their doctor before taking fennel. It may cause a reaction.
References
REFA Colic
REFA1 Perry R, Hunt K, et al. Nutritional supplements and other complementary medicines for infantile colic: a systematic review. Pediatrics. 2011 Apr;127(4):720-733.
REFA2 Harb T, Matsuyama M, et al. Infant Colic-What works: A Systematic Review of Interventions for Breast-fed Infants. J Pediatr Gastroenterol Nutr. 2016 May;62(5):668-686.
REFA3 Anheyer D, Frawley J, et al. Herbal Medicines for Gastrointestinal Disorders in Children and Adolescents: A Systematic Review. Pediatrics. 2017 Jun;139(6). pii: e20170062. doi: 10.1542/peds.2017-0062. Epub 2017 May 4. Review. PubMed PMID: 28562281.
REFB Constipation
REFB1 Picon PD, Picon RV, et al. Randomized clinical trial of a phytotherapic compound containing Pimpinella anisum, Foeniculum vulgare, Sambucus nigra, and Cassia augustifolia for chronic constipation. BMC Complement Altern Med. 2010 Apr 30;10:17.
REFC DPMA-Induced Amenorrhea
REFC1 Mohebbi-Kian E, Mohammad-Alizadeh-Charandabi S, et al. Efficacy of fennel and combined oral contraceptive on depot medroxyprogesterone acetate-induced amenorrhea: a randomized placebo-controlled trial. Contraception. 2014 Oct;90(4):440-446.
REFD Dysmenorrhea
REFD1 Ghodsi Z, Asltoghiri M. The effect of fennel on pain quality, symptoms, and menstrual duration in primary dysmenorrhea. J Pediatr Adolesc Gynecol. 2014 Oct;27(5):283-286.
REFD2 Pattanittum P, Kuntanone N, et al. Dietary supplements for dysmenorrhea. Cochrane Database of Systematic Reviews. 2016:CD002124.
REFE Irritable Bowel Syndrome
REFE1 Portincasa P, Bonfrate L, et al. Curcumin and Fennel Essential Oil Improve Symptoms and Quality of Life in Patients with Irritable Bowel Syndrome. J Gastrointestin Liver Dis. 2016;25(2):151-157.
REFF Menopause
REFF1 Rahimikian F, Rahimi R, et al. Effect of Foeniculum vulgare Mill. (fennel) on menopausal symptoms in postmenopausal women: a randomized, triple-blind, placebo-controlled trial. Menopause. 2017 Sep;24(9):1017-1021.
REFG Vaginal Atrophy
REFG1 Yaralizadeh M, Abedi P, et al. Effect of Foeniculum vulgare (fennel) vaginal cream on vaginal atrophy in postmenopausal women: A double-blind randomized placebo-controlled trial. Maturitas. 2016 Feb;84:75-80.